Commercially viable applications of the invention include, for example, off-road applications such as recreational equipment (go-karts, dune buggies, all terrain racing, etc.), cargo tie-down industry, heavy equipment applications, forklift or material handling equipment, and agricultural equipment.
The prior art safety restraint systems includes combination buckle and tongue devices incorporated in a belt or webbing system to safely secure an individual or occupant in a seat. Many of the prior art systems include a locking mechanism having a frame and a pawl for locking the tongue to the frame.
U.S. Pat. No. 3,921,262 discloses a load bearing safety belt buckle construction. The buckle includes a housing having a latch plate with a cam surface. A tongue plate having an abutment surface is inserted into the housing whereupon a spring urges the cam surface to engage with the abutment surface. U.S. Pat. No. 5,267,377 discloses a multi point buckle assembly. The buckle assembly includes a metal base. A latch member includes a latch lug biased by a latch spring for engaging an opening of a tongue.
Safety restraint systems for use in a harsh environment, such as off-road or earth moving equipment, are subject to particular problems. For example, the prior art buckle assembly frame acts in an enclosing manner that houses the sliding button and traps dust and debris between the button surfaces and the frame surfaces.
The ejection slide provides a plastic-on-plastic arrangement. Such an arrangement may suffer from galling due to the harsh dusty environment. The cover of certain prior art systems include features which introduce horizontal ledges which allow dust and debris to settle and accumulate thereupon and which eventually may gall internal components of the system. The size of the button face area is relatively small and obstructed too easily to activate, particularly by someone wearing heavy working gloves.
The prior art systems suffer other disadvantages. For example, the portion of the sliding button which acts upon the locking pawl engaging device is not sufficient. In addition, the button portion does not provide a backup in the event the primary device fails.